John, Paul, George and Ringo split in 1970, but they were still in business together. It wasn't harmonious.

When exactly did the Beatles break up? For many years, conventional wisdom has offered two options: September 1969, when, on the way to his solo set at the Toronto Rock & Roll Revival festival, John Lennon told fellow performers Eric Clapton and Klaus Voormann that he was planning to leave the Beatles, and April 1970, when, shortly before the release of what would become their final album, "Let It Be," Paul McCartney went public (after a fashion) with his decision to leave the band. Whichever date you accept, both have an air of the definitive about them. Yet the truth, suggests Peter Doggett in his elegant and deeply researched "You Never Give Me Your Money: The Beatles After the Breakup," is more difficult to pin down.

"Imagine an alternative script," he writes of McCartney's announcement, which, coming in a promotional Q & A accompanying the release of his first solo album, was elliptical at best. (Asked if his break with the Beatles was "temporary or permanent," he responded, "Temporary or permanent? I don't know.") "The 'McCartney' album is released," Doggett continues, "and its creator merely issues a cryptic comment about the Beatles, along the lines of 'Who knows what will happen?' … Later in 1970, with the 'split' still not made public, Lennon undertakes one of the frequent changes of heart that litter his career and invites the Beatles to help him record the songs inspired by his experience with [psychologist Arthur] Janov. The Beatles stumble, or stride into a new decade, and then … ?"

"You Never Give Me Your Money" posits a nuanced afterlife for the Beatles, if "afterlife" is the right word. For Doggett, their breakup was a process, beginning in late 1967, after the death of longtime manager Brian Epstein, and dragging on in some form or another to the present day. His book is remarkable for many reasons, not least that 48 years after the release of "Love Me Do," he has found a new lens (and much new information) through which to consider the band. Yet even more striking is his sense of the textures, the delicate interplay of individual and collective history, that continued to define the members of the Beatles long after they had ceased to function as a cohesive entity.

For every fan who ever longed for them to reunite, it's tantalizing just how close that prospect often was. As early as December 1970, Lennon, George Harrison and Ringo Starr booked studio time in an attempt to manipulate McCartney in a management dispute, but the bassist would not take the bait. Over the next few years, the former bandmates performed together in various configurations, live and in the studio. Perhaps the most famous of these near reunions were for Starr's 1973 album, "Ringo," on which all four Beatles played. Lesser known was the studio session Lennon and McCartney played together in Los Angeles in 1974.

There's a reason for that; Lennon was on his so-called lost weekend, estranged from Yoko Ono and living an excessive life. What they produced — a sloppy jam session revealing "no hint of the Beatles' magic, no rapport between the two men, merely a cocaine-driven Lennon berating and bullying the engineer before floundering through fragments of half-forgotten rock 'n' roll hits" — suggests the futility of looking back. Still, Doggett writes, this did not dissuade the pair from seeking other ways to collaborate, including a plan to write and record together in New Orleans at the beginning of 1975, which was scuttled after Lennon found his way back to Ono, who presumably frowned on the idea.

Of course, for all he has to tell us about the music, Doggett's main focus is on the money, and he deftly explicates the complexities of the Beatles' finances, which both bound them inextricably together and drove them irrevocably apart. The first part of the book deals with the rise and fall of Apple, the band's anti-corporate media corporation, which foundered on its own idealism. "Basically it was chaos," Doggett quotes Harrison. "We just gave away huge quantities of money. It was a lesson to anybody not to have a partnership."

It was precisely this partnership that trapped the Beatles in a series of claustrophobic legal battles, as Doggett documents. First, there was the 1969 fight over management, with Lennon, Harrison and Starr opting to be represented by New York music promoter Allen Klein, long regarded as a villain in the Beatles' saga, while Paul opted in favor of Park Avenue lawyer Lee Eastman, his new father-in-law. It's no stretch to suggest that this dispute is what destroyed the Beatles, alienating Paul from the others in ways that could never be repaired.